Heat insulation for air spaces



E. DYCKERHOFF LQSLMM HEAT INSULATION FOR AIR SPACES Original Filed April50, '1926 INVENTOR 4Eduard Dyckerhoff BY PMZI, .22a/N ATTORNEYS PatentedNov. 7, 1933 UNITED STA HEAT INSULATION FOR AIR SPACES EduardDyckerhoff,

Schloss Blumenau, Wunstorf, Germany, assignor to N. V. InternationaleMol-Maatschappij, Amsterdam, Netherlands, a corporation of theNetherlands Continuation of application Serial No. 105,753, April 30,1926, and in Germany November 23, 1925. This application March 6, 1933.Serial 12 Claims.

This application is a continuation of application Ser. No. 105,753, lledon April 30, 1926, by me, together with Ernst Schmidt, and is acontinuation in part of my earlier application, Ser. No. 442,219, illedApril 7, 1930. l

In Schmidt application, Ser. No. 635,263, illed Sept. 28, 1932, issuedas Patent No. 1,890,418, there is described and claimed the invention ofusing sheets having thin heat reiiective metal surfaces spaced apart toform air layers, as a heat insulation. This application relates to aspecic form of that invention, in which the sheets are formed of metalfoil and the means for holding the sheets in spaced relation is formedfrom the sheets themselves. Despite the fact that metal usable for thefoil, such as aluminum, has great conductivity for heat, l havediscovered that if the foil used is very thin the amount of heatconducted through the points ci contact necessary to keep the sheetsspaced will be very small, particularly where there is a substantialaverage spacing of the sheets. The foil employed for this purpose may beless than .02 mm. and may even be as thin as .005 mm., or thinner iiobtainable, but oil even of this thin, tissue, paper-like nature hassufficient rigidity relative to its weight so that a very small numberof points of contact will be sufcient to keep two sheets inproperqjp'aced relation provided they are protected against outsidepressures.

The means for spacing the insulated sheets may be formed of the sheetsthemselves in any desired manner, such as by stamping and subsequentlybending the sheets, and the insulating sheets thus formed may either beapplied immediately to the member to be insulated or used to forminsulating plates. l' have found however that the most efficient way offorming the necessary projections on the sheets is to give them acrumpling which will make the sheets uneven. This crumpling should besuch that when the sheets are/laid together they will have a substantialaverage spacing which may be, for example, in the order of about l cm.,though this may be increased or decreased somewhat as circumstancesdemand, but ordinarily will be between .5 cm. and 2 om. From this it canbe seen that where I use the expression air spaces of substantialthickness I intend to imply that the air spaces shall be substantiallygreater than those which have been suggested to be formed betweencrumpled or embossed asbestos paper which is then assembled with anadhesive or other locking means to form a co- (Cl. 15b-28) herent mass,Where the air spaces are in the form of innumerable tiny cells.

One of the great benefits of my invention is found in the easy methodwhich it supplies of insulating bodies of uneven or irregular shape.l-leretofore such bodies could only be insulated With masses of porousmaterial unless the previously built-up forms were made at greatexpense.. According to my invention, the foil can be shipped to the spotwhere it is to be used in the form of rolls which take up very littlespace, and then crumpled or distorted by hand or machine and applied tothe surface of the mem= ber to be insulated.

Foil such as I use is so thin that it has very little elasticity, withthe result that it does not tend to spring back out of the position towhich it has been formed; ralso there is substantially no tendencytoward warping or movement of the parts due to swelling and contractionfrom the effects of moisture, so that there is no necessity of lockingthesheets to each other to maintain the irregular shape necessary toprovide thick air spaces. Despite the fact that, in order to keepconduction to a minimum, l prefer to use metal so thin that theinsulation filling made of a plurality of sheets can readily becompressedwith the fingers to a thickness not over one hundredth of itsoriginal thickness, nevertheless this metal has suicient strengthrelative to its weight so that there is substantially no tendency forthe filling to pack down under the force of gravity. Thus if the sheetsare held against relative bodily movement and the filling is protectedagainst outside pressure, it will remain substantially indenitely in theform in which it is applied, even under the influence of heavy vibrationand shock.

Holding the sheets against relative bodily movement is very simple andcan be accomplished in various ways. Where the sheets are used inhorizontal position, the rst can be laid on the support and the othersheets laid over the iirst. Ordinarily in such a case there will eitherbe end members (limiting the ends of the air space) to hold the sheetsagainst shaking sideways, or else the sheets will extend down over thesides of the support to prevent relative movement. En the case where thesheets are used vertically they can be hung in any desired manner. Thusone of the simplest ways is 'to use a single sheet long enough to formtwo layers and hang this by its middle portion over some appropriatesupport positioned adjacent the top of the air space, or separate sheetscan be hung on pins spaced to the insulating eiiiciency of thestructure, andas desired. If the layers of foil do not entirely :lillthe air space, ties or bars of any desired sort may be used to preventthe sheets from separating. In the case of pipe coatings. the fact thatthe separate sheets surround the pipe will hold the layers againstrelative bodily movement and this will be true whether the layers areput on separately or in the form of a spiral.

Ordinarily it will be advisable t0 Supply aprotective casing to go overthe insulation to protect it from outside pressures.` In the case wherethe insulation is used for iilling air spaces created by the usualstructural members, as in walls or ceilings, no special casing will benecessary, but in other instances, as in making pipe coatings, anoutside shell is advisable. which may be made of metal heavier than thefoil. Such an outside shell is not however essential insulation madeaccording to my invention can be used very eiiciently for temporaryrepairs as well as for permanent installations.

. By doing away with the spacing means such as asbestos strips or thelike, it is possible greatly to reduce the weight of the insulatingstructure; in fact, the insulation of my invention can be used whereveran air space of substantial size exists, without materially increasingthe weight of the article to which it is applied. This is particularlyimportant where large areas are to be covered, for where the sheets areused in at parallel form, spacers or supports must be provided atrelatively frequent intervals, increasing the weight and cost ofmaterials and also greatly increasing the cost of application. Thus thisform of insulation is particularly adapted to all forms of vehicles bothfor land, water and air where the reduction in the weight of theinsulation permits additional pay load. If desired, the crumpled form ofinsulation may be used as a means for separating flat sheets of foil,and it is not necessary that all of the sheets be crumpled.

For the purpose of illustration, examples of my invention are shown invarious forms in the accompanying drawing, in which Fig. 1 illustratesmore or less diagrammatically a number of crumpled sheets arranged oneabove another; Fig. 2 is a sectional view of a hollow wooden wallconstruction with the improved insulation arranged therein; Fig. 3 is asection of a longitudinal pipe insulation; Fig. 4 is a cross section ofthe structure shown in Fig. 3, and Fig. 5 shows the application of myinvention to a bowed structure, for example, the roof of a railwaycarriage.

Fig. 1 is intended to convey the idea that the sheets are so crumpled asto have a small number of contacts with relatively large air spacesbetween the sheets. In Fig. 2, this type of insulation is shown in ahollow wooden wall or floor construction Where the wooden facings c arecarried by beams d; in the intermediate space the thin crumpled foil ais arranged. The individual layers of foil lie loosely one above andadjacent the other and the irregularities in the sheets form the meansfor keeping the sheets in spaced relation.

In Figs. 3 and 4 pipe b is shown insulated by means of sheets of foilarranged between the outer casing f and the outer surface of the pipe.The casing f is here illustrated as supported by means of the pins gwhich contact with the pipe but other suitable means may be employed forthis purpose. In these iigures it is to be noted case the intermediatesheet will remain ilat.

Fig. 5 shows the manner in which my invention cszn be readily attachedto a surface of irregular ape.

`From these illustrative examples it will be seen that my invention isone which can readily be applied to a great variety of uses and can beinstalled with great ease and simplicity. While my structure isprimarily intended for heat insulation it is also true that it has valueas a sound insulation.

In the appended claims the word crumpled is used to cover the case wherethe foil is either distorted irregularly by hand or is given a regular,equivalent form by machine.

What I claim iszf 1. A heat insulating body'con'sisting essentially of aplurality of layers of heat conductive metal formed into crumpled sheetsof a tissue paper-like thickness whereby transmission of heat along thesheet is reduced to a very small factor and having surfaces adapted toreflect heat, such layers contacting loosely with each other at spacedpoints to form a cellular body having air spaces of great averagethickness relative to the thickness of the foil employed.

2. A metallic mass adapted to resist the transmission of heat consistingessentially of a plurality of sheets of thin metal foil so distortedfrom planular form that the sheets contact mutually to support eachother but are held .spaced apart for the greater part of their area toform relatively large air spaces between the sheets.

3. A heat insulating structure, comprising a substantially rigid casingand a nlling for such casing, consisting essentially of a plurality oflayers of very thin crumpled metalfoil loosely supporting each other tohold the maior proportion of the area of'the sheets spaced apart to formcellular air spaces of great average thickness relative to the thicknessof the metal employed.

4. In combination, a member to be insulated,

a casing member spaced therefrom and a filling for the space betweensuch members, consisting essentially oi' sheets of very thin crumpledmetal foil lying loosely adjacent each other.

5. In combination, structural members forminganairspace,aninsulatingmassinsuchairspace comprising a plurality oflayers of crumpled metal foil of tissue paper-like thickness positionedA loosely adjacent each other so as mutually to sup port each other andto be supported by said structural members whereby a cellular structureis formed within the air space of great thickness relative to thethickness of the foil employed.

6. Structural members comprising frame members and facing membersforming an air space and heat insulation for such space essentially ofvery thin metal foil crumpled to contact with such structural members atspaced points whereby such foil will be supported by such members withrelatively large air spaces on both sides of such foil.

7. An insulating structure comprising a filling consisting essentiallyof a plurality of layers of crumpled foil loosely contacting with andmutually supporting each other at spaced points to form air layers ofsubstantial average thickness char- 150 acterized by the fact that suchfilling is made of metal so thin that it has substantially no structuralstrength and such that the lling can readily be compressed with thefingers to a thickness not over one hundredth of its original thickness,whereby transmission of heat by conduction is largely prevented, yetwill remain substantially indenitely in its desired form, and a casingfor such filling adapted to hold the sheets against relative bodilymovement and protect them from outside pressure. 5

8. The method of insulating structures which comprises the steps ofloosely applying a plurality of layers of crumpled, very thin metallicfoil against a member to be insulated so that the layers mutuallysupport each other to maintain air spaces of great thickness relative tothe thickness ofthe foil, and enclosing such layers of foil in asubstantially rigid structure adapted to hold such layers of foilagainst relative bodily movement.

9. The method of heat insulating non-plane members which comprises thestep of orumpling a sheet of very thin metal foil, shaping such sheetabout the contour of the member to be insulated, loosely applying anadditional sheet of said crumpled foil adjacent such flrst -sheetwhereby the sheets are mutually supported to form a cellular body, andenclosing such sheets in a substantially rigid structure.

10. Heat insulating means for preventing radiation, as Well asconduction and convection of heat from an object, consisting of aplurality of sheets of bright aluminum foil-surrounding the object butspaced therefrom and from each other, and a filling of crumpled foil insaid spaces.

11. A structure comprising facing members and frame members forming airspaces, and thin sheet material with heat reflective metallic facesinterposed in such spaces,'such material being so distorted from planeform as to contact with the .facing members at spaced points and therebymaintain air spaces of substantial thickness on both sides of suchmaterial.

12. In combination, facing members and frame members forming air spacesand a filling for sucl'i Aspaces consisting essentially of sheets ofthin sheet material having heat reflective metallic faces distorted fromplane form and disposed in such spaces so that the shape of the sheetsholds .them With substantial air spaces on both sides.

EDUARD DYCKERHOFF.

